An Enantioselective Synthesis of (2S,3R)-3-(N-Benzyloxycarbonyl)amino-1-chloro-4-phenylthiobutan-2-ol, a Central Intermediate of Nelfinavir1

(2 S,3 R )-3-( N -Benzyloxycarbonyl)amino-1-chloro-4-phenylthiobutan-2-ol 1 is a central intermediate of nelfinavir 2, which, being a potent HIV protease inhibitor, represents one of the most clinically efficacious anti AIDS drugs. Thus, a practical enantioselective synthesis of 1 has been devised which employs sodium erythorbate 9 as a chiral starting material. Consisting of the total 14-step functional group manipulations that proceed via methyl (2 S,3 R )-4-hydroxy-2,3-epoxybutyrate 8, the synthetic processes can dispense with chromatographic purification and provide architecturally complex 1 in 17% overall yield under a strict control of stereochemistry.